Effect of some herbicides on cow pea plants inoculated with arbuscular mycorrhizal fungi and rhizohia

ABSTRACT

Two field experiments were conducted [during 1996 and 1997 seasons] to investigate the effect of the herbicides; dinitramine, fluazifop-butyl and paraquat at a rate of 1.0 l/fed. on cowpea plants inoculated with Rhizobium and/or arbuscular-mycorrhizal fungi [Glomus sp.] in a clay loam soil. All herbicides + rhizobia + AM fungi treatments showed significant increase in all growth characters of cowpea plants after 60 days from sowing as well as pod length, weight of green and dry pods per plant and weight of 100 seeds at harvest compared to unweeded control. Nodulation significantly increased on cowpea plants inoculated with rhizobia and AM fungi singly or in combination with different herbicides used compared to nodulation of plants grown on unweeded plots and inoculated with rhizobia or AM fungi singly or in combination. Application of the different herbicides significantly decreased mycorrhizal spore numbers in all treatments expected treatment inoculated with rhizobia singly and application of dinitramine. However, no significant was found in mycorrhizal root colonization between all treatments